Methods for delivering energy into a target tissue of a body

ABSTRACT

An instrument and method for tissue thermotherapy including an inductive heating means to generate a vapor phase media that is used for interstitial, intraluminal, intracavity or topical tissue treatment. In one method, the vapor phase media is propagated from a probe outlet to provide a controlled vapor-to-liquid phase change in an interface with tissue to thereby apply ablative thermal energy delivery.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/555,635 filed Sep. 8, 2009, which claims benefit of U.S. ProvisionalApplication No. 61/191,459 filed on Sep. 9, 2008, the content of each ofwhich is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention relates to medical instruments and systems for applyingenergy to tissue, and more particularly relates to a system forablating, sealing, welding, coagulating, shrinking or creating lesionsin tissue by means of contacting a targeted tissue in a patient with avapor phase media wherein a subsequent vapor-to-liquid phase change ofthe media applies thermal energy to the tissue to cause an intendedtherapeutic effect. Variations of the invention include devices andmethods for generating a flow of high quality vapor and monitoring thevapor flow for various parameters with one or more sensors. In yetadditional variations, the invention includes devices and methods formodulating parameters of the system in response to the observedparameters.

BACKGROUND OF THE INVENTION

Various types of medical instruments utilizing radiofrequency (Rf)energy, laser energy, microwave energy and the like have been developedfor delivering thermal energy to tissue, for example to ablate tissue.While such prior art forms of energy delivery work well for someapplications, Rf, laser and microwave energy typically cannot causehighly “controlled” and “localized” thermal effects that are desirablein controlled ablation of soft tissue for ablating a controlled depth orfor the creation of precise lesions in such tissue. In general, thenon-linear or non-uniform characteristics of tissue affectelectromagnetic energy distributions in tissue.

What is needed are systems and methods that controllably apply thermalenergy in a controlled and localized manner without the lack of controloften associated when Rf, laser and microwave energy are applieddirectly to tissue.

SUMMARY OF THE INVENTION

The present invention is adapted to provide improved methods ofcontrolled thermal energy delivery to localized tissue volumes, forexample for ablating, sealing, coagulating or otherwise damagingtargeted tissue, for example to ablate a tissue volume interstitially orto ablate the lining of a body cavity. Of particular interest, themethod causes thermal effects in targeted tissue without the use of Rfcurrent flow through the patient's body and without the potential ofcarbonizing tissue. The devices and methods of the present disclosureallow the use of such energy modalities to be used as an adjunct ratherthan a primary source of treatment.

One variation of the present novel method includes a method ofdelivering energy into a target tissue of a body region, the methodcomprising advancing a working end of a device into the body region,expanding a structure from within a working end of the device into thebody region, where at least a portion of the thin wall structure ispermeable to allow transfer of a medium through the structure to thetissue, and delivering an amount of energy from the structure to treatthe target tissue of the body region.

Expanding the structure can include everting the structure. Although thevariations described below discuss everting the structure, alternatevariations can include inflating, unfolding, unfurling or unrolling thestructure. Typically, these different expansion modes relate to themanner in which the structure is located (partially or fully) within theworking end of the device. In any case, many variations of the methodand device allow for the structure to expand to (or substantially to)the cavity or tissue region being treated. As such, the structure cancomprise a thin wall structure or other structure that allows fordelivery of the vapor media therethrough. Expansion of the structure canoccur using a fluid or gas. Typically the expansion pressure is low,however, alternate variations can include the use of high pressureexpansion. In such a variation, the expansion of the structure can beused to perform a therapeutic treatment in conjunction with the energydelivery.

Typically, the energy applied by the vapor media is between 25 W and 150W. In additional variations, the vapor media can apply a first amount ofenergy with alternate energy modalities being used to provide additionalamounts of energy as required by the particular application ortreatment. Such additional energy modalities include RF energy, lightenergy, radiation, resistive heating, chemical energy and/or microwaveenergy. In some cases, the treatment ablates the target tissue. Inalternate variations, the treatment coagulates or heats the tissue toaffect a therapeutic purpose. The additional modalities of energy can beapplied from elements that are in the expandable structure or on asurface of the structure.

Turning now to the vapor delivery, as described below, the vaportransfers an amount of energy to the tissue without charring ordesiccating the tissue. In certain variations, delivering the amount ofenergy comprises delivering energy using a vapor media by passing thevapor media through the structure. Accordingly, the expandable structurecan include at least one vapor outlet. However, additional variations ofthe method or device can include structures that include a plurality ofpermeable portions, where at least a porosity of one of the permeableportion varies such that delivery of the amount of energy is non-uniformabout the structure when expanded. In one example, delivering the amountof energy comprises delivering a first amount of energy at a centralportion of the structure when expanded and a second amount of energy ata distal or proximal portion, and where the first amount of energy isdifferent than the second amount of energy.

In those variations that employ additional energy delivery means, asecond amount of energy can be delivered from a portion of thestructure. For example, electrodes, antennas, or emitters, can bepositioned on or within the structure.

The structures included within the scope of the methods and devicesdescribed herein can include any shape as required by the particularapplication. Such shapes include, but are not limited to round,non-round, flattened, cylindrical, spiraling, pear-shaped, triangular,rectangular, square, oblong, oblate, elliptical, banana-shaped,donut-shaped, pancake-shaped or a plurality or combination of suchshapes when expanded. The shape can even be selected to conform to ashape of a cavity within the body (e.g., a passage of the esophagus, achamber of the heart, a portion of the GI tract, the stomach, bloodvessel, lung, uterus, cervical canal, fallopian tube, sinus, airway,gall bladder, pancreas, colon, intestine, respiratory tract, etc.)

In additional variations, the devices and methods described herein caninclude one or more additional expanding members. Such additionalexpanding members can be positioned at a working end of the device. Thesecond expandable member can include a surface for engaging anon-targeted region to limit the energy from transferring to thenon-targeted region. The second expandable member can be insulated toprotect the non-targeted region. Alternatively, or in combination, thesecond expandable member can be expanded using a cooling fluid where theexpandable member conducts cooling to the non-targeted region. Clearly,any number of additional expandable members can be used. In onevariation, an expandable member can be used to seal an opening of thecavity.

In certain variations, the device or method includes the use of one ormore vacuum passages so that upon monitoring a cavity pressure withinthe cavity, to relieve pressure when the cavity pressure reaches apre-determined value.

In another variation, a device according to the present disclosure caninclude an elongated device having an axis and a working end, a vaporsource communicating with at least one vapor outlet in the working end,the vapor source providing a condensable vapor through the vapor outletto contact the targeted tissue region, such that when the condensablevapor contacts the targeted tissue region, an amount of energy transfersfrom the condensable vapor to the targeted tissue region, and at leastone expandable member is carried by the working end, the expandablemember having a surface for engaging a non-targeted tissue region tolimit contact and energy transfer between the condensable vapor and thenon-targeted tissue region.

In one variation a first and second expandable members are disposedaxially proximal of the at least one vapor outlet. This allows treatmentdistal to the expandable members. In another variation, at least onevapor outlet is intermediate the first and second expandable members.Therefore, the treatment occurs between the expandable members. In yetanother variation, at least one expandable member is radially positionedrelative to at least one vapor outlet to radially limit the condensablevapor from engaging the non-targeted region.

In additional variation of the methods and devices, the expandablemember(s) is fluidly coupled to a fluid source for expanding theexpandable member. The fluid source can optionally comprise a coolingfluid that allows the expandable member to cool tissue via conductionthrough the surface of the expandable member.

In another variation of a method under the principles of the presentinvention, the method includes selectively treating a target region oftissue and preserving a non-target region of tissue within a bodyregion. For example, the method can include introducing a working end ofan axially-extending vapor delivery tool into cavity or lumen, theworking end comprising at least one vapor outlet being fluidlycoupleable to a vapor source having a supply of vapor, expanding atleast one expandable member carried by the working end to engage thenon-target region of tissue, and delivering the vapor through the vaporoutlet to the target region tissue to cause energy exchange between thevapor and the target region tissue such that vapor contact between thenon-target region of tissue is minimized or prevented by the at leastone expanding member.

The methods described herein can also include a variation of treatingesophageal tissue of a patient's body. In such a case, any of thevariations of the devices described herein can be used. In any case, anexample of the method includes introducing an elongate vapor deliverytool into an esophageal passage, the vapor delivery tool beingcoupleable to a supply of vapor, delivering the vapor through thedelivery tool into the passage, and controlling energy application to asurface of the passage by controlling interaction between the vapor andthe surface of the passage. In an additional variation, the elongatevapor delivery tool includes a vapor lumen and a vacuum lumen, where thevapor lumen and vacuum lumen are in fluid communication, wherecontrolling interaction between the vapor and the surface of the passagecomprises modulating delivery of a vapor inflow through the vapor lumenand modulating vacuum outflow through the vacuum lumen. The method canfurther include applying a cooling media to the surface of the passageto limit diffusion of heat in the surface.

Methods of the present disclosure also include methods of reducingdiabetic conditions. For example, the method can include treating apatient to reduce diabetic conditions by inserting a vapor deliverydevice to an digestive passage, where the vapor delivery device iscoupleable to a source of vapor, delivering the vapor to a wall of thedigestive tract to transfer energy from the vapor to the wall in asufficient amount to alter a function of the digestive tract, andcontrolling interaction between the vapor and the wall to causecontrolled ablation at the a treatment area. The treatment can beapplied in an organ selected from the group consisting of the stomach,the small intestines, the large intestines, and the duodenum. In somevariations, controlling interaction between the vapor and the wallcauses a thin ablation layer on a surface of the wall.

The present disclosure also includes medical systems for applyingthermal energy to tissue, where the system comprises an elongated probewith an axis having an interior flow channel extending to at least oneoutlet in a probe working end; a source of vapor media configured toprovide a vapor flow through at least a portion of the interior flowchannel, wherein the vapor has a minimum temperature; and at least onesensor in the flow channel for providing a signal of at least one flowparameter selected from the group one of (i) existence of a flow of thevapor media, (ii) quantification of a flow rate of the vapor media, and(iii) quality of the flow of the vapor media. The medical system caninclude variations where the minimum temperature varies from at least80° C., 100° C. 120° C., 140° C. and 160° C. However, other temperatureranges can be included depending upon the desired application.

Sensors included in the above system include temperature sensor, animpedance sensor, a pressure sensor as well as an optical sensor.

The source of vapor media can include a pressurized source of a liquidmedia and an energy source for phase conversion of the liquid media to avapor media. In addition, the medical system can further include acontroller capable of modulating a vapor parameter in response to asignal of a flow parameter; the vapor parameter selected from the groupof (i) flow rate of pressurized source of liquid media, (ii) inflowpressure of the pressurized source of liquid media, (iii) temperature ofthe liquid media, (iv) energy applied from the energy source to theliquid media, (v) flow rate of vapor media in the flow channel, (vi)pressure of the vapor media in the flow channel, (vi) temperature of thevapor media, and (vii) quality of vapor media.

In another variation, a novel medical system for applying thermal energyto tissue comprises an elongated probe with an axis having an interiorflow channel extending to at least one outlet in a probe working end,wherein a wall of the flow channel includes an insulative portion havinga thermal conductivity of less than a maximum thermal conductivity; anda source of vapor media configured to provide a vapor flow through atleast a portion of the interior flow channel, wherein the vapor has aminimum temperature.

Variations of such systems include systems where the maximum thermalconductivity ranges from 0.05 W/mK, 0.01 W/mK and 0.005 W/mK.

Methods are disclosed herein for thermally treating tissue by providinga probe body having a flow channel extending therein to an outlet in aworking end, introducing a flow of a liquid media through the flowchannel and applying energy to the tissue by inductively heating aportion of the probe sufficient to vaporize the flowing media within theflow channel causing pressurized ejection of the media from the outletto the tissue.

The methods can include applying energy between 10 and 10,000 Joules tothe tissue from the media. The rate at which the media flows can becontrolled as well.

In another variation, the methods described herein include inductivelyheating the portion of the probe by applying an electromagnetic energysource to a coil surrounding the flow channel. The electromagneticenergy can also inductively heat a wall portion of the flow channel.

Another variation of the method includes providing a flow permeablestructure within the flow channel. Optionally, the coil described hereincan heat the flow permeable structure to transfer energy to the flowmedia. Some examples of a flow permeable structure include wovenfilaments, braided filaments, knit filaments, metal wool, a microchannelstructure, a porous structure, a honeycomb structure and an open cellstructure. However, any structure that is permeable to flow can beincluded.

The electromagnetic energy source can include an energy source rangingfrom a 10 Watt source to a 500 Watt source.

Medical systems for treating tissue are also described herein. Suchsystems can include a probe body having a flow channel extending thereinto an outlet in a working end, a coil about at least a portion or theflow channel, and an electromagnetic energy source coupled to the coil,where the electromagnetic energy source induces current in the coilcausing energy delivery to a flowable media in the flow channel. Thesystems can include a source of flowable media coupled to the flowchannel. The electromagnetic energy source can be capable of applyingenergy to the flowable media sufficient to cause a liquid-to-vapor phasechange in at least a portion of the flowable media as described indetail herein. In addition the probe can include a sensor selected froma temperature sensor, an impedance sensor, a capacitance sensor and apressure sensor. In some variations the probe is coupled to anaspiration source.

The medical system can also include a controller capable of modulatingat least one operational parameter of the source of flowable media inresponse to a signal from a sensor. For example, the controller can becapable of modulating a flow of the flowable media. In anothervariation, the controller is capable of modulating a flow of theflowable media to apply between 100 and 10,000 Joules to the tissue.

The systems described herein can also include a metal portion in theflow channel for contacting the flowable media. The metal portion can bea flow permeable structure and can optionally comprise a microchannelstructure. In additional variations, the flow permeable structure caninclude woven filaments, braided filaments, knit filaments, metal wool,a porous structure, a honeycomb structure, an open cell structure or acombination thereof.

In another variation, the methods described herein can includepositioning a probe in an interface with a targeted tissue, and causinga vapor media from to be ejected from the probe into the interface withtissue wherein the media delivers energy ranging from 5 joules to100,000 joules to cause a therapeutic effect, wherein the vapor media isconverted from a liquid media within the probe by inductive heatingmeans.

Methods described herein also include methods of treating tissue byproviding medical system including a heat applicator portion forpositioning in an interface with targeted tissue, and converting aliquid media into a vapor media within an elongated portion of themedical system having a flow channel communicating with a flow outlet inthe heat applicator portion, and contacting the vapor media with thetargeted tissue to thereby deliver energy ranging from 5 joules to100,000 joules to cause a therapeutic effect.

As discussed herein, the methods can include converting the liquid intoa vapor media using an inductive heating means. In an alternatevariation, a resistive heating means can be combined with the inductiveheating means or can replace the inductive heating means.

The instrument and method of the invention can cause an energy-tissueinteraction that is imagable with intra-operative ultrasound or MRI.

The instrument and method of the invention cause thermal effects intissue that do not rely on applying an electrical field across thetissue to be treated.

Additional advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

All patents, patent applications and publications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication or patent application was specificallyand individually indicated to be incorporated by reference.

In addition, it is intended that combinations of aspects of the systemsand methods described herein as well as the various embodimentsthemselves, where possible, are within the scope of this disclosure.

This application is related to the following U.S. Non-provisional andProvisional applications: Application No. 61/126,647 Filed on May 6,2008 MEDICAL SYSTEM AND METHOD OF USE; Application No. 61/126,651 Filedon May 6, 2008 MEDICAL SYSTEM AND METHOD OF USE; Application No.61/126,612 Filed on May 6, 2008 MEDICAL SYSTEM AND METHOD OF USE;Application No. 61/126,636 Filed on May 6, 2008 MEDICAL SYSTEM ANDMETHOD OF USE; Application No. 61/130,345 Filed on May 31, 2008 MEDICALSYSTEM AND METHOD OF USE; Application No. 61/066,396 Filed on Feb. 20,2008 TISSUE ABLATION SYSTEM AND METHOD OF USE; Application No.61/123,416 Filed on Apr. 8, 2008 MEDICAL SYSTEM AND METHOD OF USE;Application No. 61/068,049 Filed on Mar. 4, 2008 MEDICAL SYSTEM ANDMETHOD OF USE; Application No. 61/123,384 Filed on Apr. 8, 2008 MEDICALSYSTEM AND METHOD OF USE; Application No. 61/068,130 Filed on Mar. 4,2008 MEDICAL SYSTEM AND METHOD OF USE; Application No. 61/123,417 Filedon Apr. 8, 2008 MEDICAL SYSTEM AND METHOD OF USE; Application No.61/123,412 Filed on Apr. 8, 2008 MEDICAL SYSTEM AND METHOD OF USE;Application No. 61/126,830 Filed on May 7, 2008 MEDICAL SYSTEM ANDMETHOD OF USE; and Application No. 61/126,620 Filed on May 6, 2008MEDICAL SYSTEM AND METHOD OF USE.

The systems and methods described herein are also related to U.S. patentapplication Ser. No. 10/681,625 filed Oct. 7, 2003 titled “MedicalInstruments and Techniques for Thermally-Mediated Therapies”; Ser. No.11/158,930 filed Jun. 22, 2005 titled “Medical Instruments andTechniques for Treating Pulmonary Disorders”; Ser. No. 11/244,329 filedOct. 5, 2005 titled “Medical Instruments and Methods of Use” and Ser.No. 11/329,381 filed Jan. 10, 2006 titled “Medical Instrument and Methodof Use”.

All of the above applications are incorporated herein by this referenceand made a part of this specification, together with the specificationsof all other commonly-invented applications cited in the aboveapplications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a graphical depiction of the quantity of energy needed toachieve the heat of vaporization of water.

FIG. 1B is a diagram of phase change energy release that underlies asystem and method of the invention.

FIG. 2 shows a schematic view of a medical system that is adapted fortreating a target region of tissue.

FIG. 3 is a block diagram of a control method of the invention.

FIG. 4A is an illustration of the working end of FIG. 2 being introducedinto soft tissue to treat a targeted tissue volume.

FIG. 4B is an illustration of the working end of FIG. 4A showing thepropagation of vapor media in tissue in a method of use in ablating atumor.

FIG. 5 is an illustration of a working end similar to FIGS. 4A-4B withvapor outlets comprising microporosities in a porous wall.

FIG. 6A is schematic view of a needle-type working end of a vapordelivery tool for applying energy to tissue.

FIG. 6B is schematic view of an alternative needle-type working endsimilar to FIG. 6A.

FIG. 6C is schematic view of a retractable needle-type working endsimilar to FIG. 6B.

FIG. 6D is schematic view of working end with multiple shape-memoryneedles.

FIG. 6E is schematic view of a working end with deflectable needles.

FIG. 6F is schematic view of a working end with a rotating element fordirecting vapor flows.

FIG. 6G is another view of the working end of FIG. 6F.

FIG. 6H is schematic view of a working end with a balloon.

FIG. 6I is schematic view of an articulating working end.

FIG. 6J is schematic view of an alternative working end with RFelectrodes.

FIG. 6K is schematic view of an alternative working end with a resistiveheating element.

FIG. 6L is schematic view of a working end with a tissue-capturing loop.

FIG. 6M is schematic view of an alternative working end with jaws forcapturing and delivering vapor to tissue.

FIG. 7 shows an embodiment of a sensor system that is carried by workingend of a probe depicted in FIG. 2 for determining a first vapor mediaflow parameter.

FIG. 8 shows a sensor configured for indicating vapor quality—in thiscase based on a plurality of spaced apart electrodes.

FIG. 9 is a partly disassembled view of a handle and inductive vaporgenerator system of the invention.

FIG. 10 is an enlarged schematic view of the inductive vapor generatorof FIG. 9.

FIG. 11A is a sectional view of the working end of a vapor delivery toolcomprising an introducer carrying an expandable structure for deliveringvapor from outlets therein.

FIG. 11B is a view of the structure of FIG. 11A depicting an initialstep of a method of expanding the thin-wall structure in a body cavity.

FIG. 11C is a sectional view of a structure of FIG. 11B in a deployed,expanded configuration depicting the step of delivering vapor intotissue surrounding the body cavity.

FIG. 12A is a schematic view of the handle and working end of vapordelivery tool for treating an esophageal disorder such as Barrett'sesophagus.

FIG. 12B is another view of the vapor delivery tool of FIG. 12Aillustrating an initial step of a method of the invention comprisingexpanding proximal and distal occlusion balloons to define a treatmentsite between the balloons.

FIG. 12C is view similar to that of FIG. 12B illustrating a subsequentstep of expanding one or more additional occlusion balloons to furthercircumscribe the targeted treatment site and the step of deliveringvapor to ablate the esophageal lumen.

FIG. 13 is view similar to that of FIGS. 12A-12C illustrating analternative embodiment and method for using a scalloped balloon forproviding a less than 360° ablation the esophageal lumen.

FIG. 14 depicts and alternative method for accomplishing a localablation within the esophageal lumen utilizing an elongated vapordelivery tool introduced through a working channel of an endoscope.

FIG. 15 is a sectional view of the working end of the vapor deliverytool of FIG. 14 showing vapor outlets that cooperates with an aspirationlumen for local control of vapor contact with tissue.

FIG. 16A is a schematic view of the working end of an alternative vapordelivery tool configured for endometrial ablation within a patient'suterus, and the initial step of introducing the working end a uterinecavity wherein the working end carries a plurality of expandable membersfor occluding and sealing the endocervical canal.

FIG. 16B is a schematic view similar to FIG. 16A illustrating the stepof expanding a primary balloon in the endocervical canal.

FIG. 16C is a schematic view similar to FIG. 16B illustrating thesubsequent step of expanding a second more distal balloon and sensingwhether the balloon is proximal or distal from the internal os.

FIG. 16D is another view as in FIGS. 16B-16C illustrating the subsequentstep of expanding a third more distal balloon and sensing whether theballoon is proximal or distal from the internal os.

FIG. 16E is another view as in FIGS. 16B-16D illustrating the subsequentstep of expanding a fourth more distal balloon and sensing whether theballoon is proximal or distal from the internal os.

FIG. 16F is a view similar to FIGS. 16B-16E illustrating the steps of(i) selecting which of the second, third and fourth balloons are toremain expanded to protect the endocervical canal, (ii) evening athin-wall evening structure into the uterine cavity, and (iii)delivering vapor from a plurality of vapor outlets in the evertingstructure to provide a global endometrial ablation.

FIG. 17 is a lateral sectional view of the working end of FIG. 16Fdepicting how the everting thin-wall structure deploys atraumaticallywithin the uterine cavity.

FIG. 18 is a perspective view of an alternative thin-wall evertingstructure for endometrial ablation that is similar to that of FIGS. 16Fand 17, the structure carrying opposing polarity electrode surfaces forapplying RF energy to tissue contemporaneous with applied energy from acondensable vapor.

FIG. 19 is a cut-away view of the thin-wall evening structure of FIG. 18showing a plurality of vapor delivery channels in the surfaces of theevening structure.

FIG. 20 is a schematic view of the working end of an alternative vapordelivery tool configured for applying ablative energy to an intestinallumen to treat a diabetic disorder, wherein the working end carries aplurality of expandable members for occluding and sealing the lumensimilar to the methods depicted in FIGS. 12A-12C and FIGS. 16A-16F.

DETAILED DESCRIPTION OF THE INVENTION

As used in the specification, “a” or “an” means one or more. As used inthe claim(s), when used in conjunction with the word “comprising”, thewords “a” or “an” mean one or more. As used herein, “another” means asleast a second or more. “Substantially” or “substantial” mean largelybut not entirely. For example, substantially may mean about 10% to about99.999, about 25% to about 99.999% or about 50% to about 99.999%.

In general, the thermally-mediated treatment method comprises causing avapor-to-liquid phase state change in a selected media at a targetedtissue site thereby applying thermal energy substantially equal to theheat of vaporization of the selected media to the tissue site. Thethermally-mediated therapy can be delivered to tissue by suchvapor-to-liquid phase transitions, or “internal energy” releases, aboutthe working surfaces of several types of instruments for ablativetreatments of soft tissue. FIGS. 1A and 1B illustrate the phenomena ofphase transitional releases of internal energies. Such internal energyinvolves energy on the molecular and atomic scale—and in polyatomicgases is directly related to intermolecular attractive forces, as wellas rotational and vibrational kinetic energy. In other words, the methodof the invention exploits the phenomenon of internal energy transitionsbetween gaseous and liquid phases that involve very large amounts ofenergy compared to specific heat.

It has been found that the controlled application of such energy in acontrolled media-tissue interaction solves many of the vexing problemsassociated with energy-tissue interactions in Rf, laser and ultrasoundmodalities. The apparatus of the invention provides a vaporizationchamber in the interior of an instrument, in an instrument's working endor in a source remote from the instrument end. A source provides liquidmedia to the interior vaporization chamber wherein energy is applied tocreate a selected volume of vapor media. In the process of theliquid-to-vapor phase transition of a liquid media, for example water,large amounts of energy are added to overcome the cohesive forcesbetween molecules in the liquid, and an additional amount of energy isrequired to expand the liquid 1000+ percent (PAD) into a resulting vaporphase (see FIG. 1A). Conversely, in the vapor-to-liquid transition, suchenergy will be released at the phase transition at the interface withthe targeted tissue site. That is, the heat of vaporization is releasedat the interface when the media transitions from gaseous phase to liquidphase wherein the random, disordered motion of molecules in the vaporregain cohesion to convert to a liquid media. This release of energy(defined as the capacity for doing work) relating to intermolecularattractive forces is transformed into therapeutic heat for athermotherapy at the interface with the targeted body structure. Heatflow and work are both ways of transferring energy.

In FIG. 1A, the simplified visualization of internal energy is usefulfor understanding phase transition phenomena that involve internalenergy transitions between liquid and vapor phases. If heat were addedat a constant rate in FIG. 1A (graphically represented as 5 calories/gmblocks) to elevate the temperature of water through its phase change toa vapor phase, the additional energy required to achieve the phasechange (latent heat of vaporization) is represented by the large numberof 110+ blocks of energy at 100° C. in FIG. 1A. Still referring to FIG.1A, it can be easily understood that all other prior art ablationmodalities—Rf, laser, microwave and ultrasound—create energy densitiesby simply ramping up calories/gm as indicated by the temperature rangefrom 37° C. through 100° C. as in FIG. 1A. The prior art modalities makeno use of the phenomenon of phase transition energies as depicted inFIG. 1A.

FIG. 1B graphically represents a block diagram relating to energydelivery aspects of the present invention. The system provides forinsulative containment of an initial primary energy-media interactionwithin an interior vaporization chamber of medical thermotherapy system.The initial, ascendant energy-media interaction delivers energysufficient to achieve the heat of vaporization of a selected liquidmedia, such as water or saline solution, within an interior of thesystem. This aspect of the technology requires a highly controlledenergy source wherein a computer controller may need to modulate energyapplication between very large energy densities to initially surpass thelatent heat of vaporization with some energy sources (e.g. a resistiveheat source, an Rf energy source, a light energy source, a microwaveenergy source, an ultrasound source and/or an inductive heat source) andpotential subsequent lesser energy densities for maintaining a highvapor quality. Additionally, a controller must control the pressure ofliquid flows for replenishing the selected liquid media at the requiredrate and optionally for controlling propagation velocity of the vaporphase media from the working end surface of the instrument. In use, themethod of the invention comprises the controlled application of energyto achieve the heat of vaporization as in FIG. 1A and the controlledvapor-to-liquid phase transition and vapor exit pressure to therebycontrol the interaction of a selected volume of vapor at the interfacewith tissue. The vapor-to-liquid phase transition can deposit 400, 500,600 or more cal/gram within the targeted tissue site to perform thethermal ablation with the vapor in typical pressures and temperatures.

Treatment Liquid Source, Energy Source, Controller

Referring to FIG. 2, a schematic view of medical system 100 of thepresent invention is shown that is adapted for treating a tissue target,wherein the treatment comprises an ablation or thermotherapy and thetissue target can comprise any mammalian soft tissue to be ablated,sealed, contracted, coagulated, damaged or treated to elicit an immuneresponse. The system 100 includes an instrument or probe body 102 with aproximal handle end 104 and an extension portion 105 having a distal orworking end indicated at 110. In one embodiment depicted in FIG. 2, thehandle end 104 and extension portion 105 generally extend aboutlongitudinal axis 115. In the embodiment of FIG. 2, the extensionportion 105 is a substantially rigid tubular member with at least oneflow channel therein, but the scope of the invention encompassesextension portions 105 of any mean diameter and any axial length, rigidor flexible, suited for treating a particular tissue target. In oneembodiment, a rigid extension portion 105 can comprise a 20 Ga. to 40Ga. needle with a short length for thermal treatment of a patient'scornea or a somewhat longer length for treating a patient's retina. Inanother embodiment, an elongate extension portion 105 of a vapordelivery tool can comprise a single needle or a plurality of needleshaving suitable lengths for tumor or soft tissue ablation in a liver,breast, gall bladder, prostate, bone and the like. In anotherembodiment, an elongate extension portion 105 can comprise a flexiblecatheter for introduction through a body lumen to access at tissuetarget, with a diameter ranging from about 1 to 10 mm. In anotherembodiment, the extension portion 105 or working end 110 can bearticulatable, deflectable or deformable. The probe handle end 104 canbe configured as a hand-held member, or can be configured for couplingto a robotic surgical system. In another embodiment, the working end 110carries an openable and closeable structure for capturing tissue betweenfirst and second tissue-engaging surfaces, which can comprise actuatablecomponents such as one or more clamps, jaws, loops, snares and the like.The proximal handle end 104 of the probe can carry various actuatormechanisms known in the art for actuating components of the system 100,and/or one or more footswitches can be used for actuating components ofthe system.

As can be seen in FIG. 2, the system 100 further includes a source 120of a flowable liquid treatment media 121 that communicates with a flowchannel 124 extending through the probe body 102 to at least one outlet125 in the working end 110. The outlet 125 can be singular or multipleand have any suitable dimension and orientation as will be describedfurther below. The distal tip 130 of the probe can be sharp forpenetrating tissue, or can be blunt-tipped or open-ended with outlet125. Alternatively, the working end 110 can be configured in any of thevarious embodiments shown in FIGS. 6A-6M and described further below.

In one embodiment shown in FIG. 2, an RF energy source 140 isoperatively connected to a thermal energy source or emitter (e.g.,opposing polarity electrodes 144 a, 144 b) in interior chamber 145 inthe proximal handle end 104 of the probe for converting the liquidtreatment media 121 from a liquid phase media to a non-liquid vaporphase media 122 with a heat of vaporization in the range of 60° C. to200° C., or 80° C. to 120° C. A vaporization system using Rf energy andopposing polarity electrodes is disclosed in co-pending U.S. patentapplication Ser. No. 11/329,381 which is incorporated herein byreference. Another embodiment of vapor generation system is described inbelow in the Section titled “INDUCTIVE VAPOR GENERATION SYSTEMS”. In anysystem embodiment, for example in the system of FIG. 2, a controller 150is provided that comprises a computer control system configured forcontrolling the operating parameters of inflows of liquid treatmentmedia source 120 and energy applied to the liquid media by an energysource to cause the liquid-to-vapor conversion. The vapor generationsystems described herein can consistently produce a high quality vaporhaving a temperature of at least 80° C., 100° C. 120° C., 140° C. and160° C.

As can be seen in FIG. 2, the medical system 100 can further include anegative pressure or aspiration source indicated at 155 that is in fluidcommunication with a flow channel in probe 102 and working end 110 foraspirating treatment vapor media 122, body fluids, ablation by-products,tissue debris and the like from a targeted treatment site, as will befurther described below. In FIG. 2, the controller 150 also is capableof modulating the operating parameters of the negative pressure source155 to extract vapor media 122 from the treatment site or from theinterior of the working end 110 by means of a recirculation channel tocontrol flows of vapor media 122 as will be described further below.

In another embodiment, still referring to FIG. 2, medical system 100further includes secondary media source 160 for providing an inflow of asecond media, for example a biocompatible gas such as CO₂. In onemethod, a second media that includes at least one of depressurized CO₂,N₂, O₂ or H₂O can be introduced and combined with the vapor media 122.This second media 162 is introduced into the flow of non-ionized vapormedia for lowering the mass average temperature of the combined flow fortreating tissue. In another embodiment, the medical system 100 includesa source 170 of a therapeutic or pharmacological agent or a sealantcomposition indicated at 172 for providing an additional treatmenteffect in the target tissue. In FIG. 2, the controller indicated at 150also is configured to modulate the operating parameters of source 160and 170 to control inflows of a secondary vapor 162 and therapeuticagents, sealants or other compositions indicated at 172.

In FIG. 2, it is further illustrated that a sensor system 175 is carriedwithin the probe 102 for monitoring a parameter of the vapor media 122to thereby provide a feedback signal FS to the controller 150 by meansof feedback circuitry to thereby allow the controller to modulate theoutput or operating parameters of treatment media source 120, energysource 140, negative pressure source 155, secondary media source 160 andtherapeutic agent source 170. The sensor system 175 is further describedbelow, and in one embodiment comprises a flow sensor to determine flowsor the lack of a vapor flow. In another embodiment, the sensor system175 includes a temperature sensor. In another embodiment, sensor system175 includes a pressure sensor. In another embodiment, the sensor system175 includes a sensor arrangement for determining the quality of thevapor media, e.g., in terms or vapor saturation or the like. The sensorsystems will be described in more detail below.

Now turning to FIGS. 2 and 3, the controller 150 is capable of alloperational parameters of system 100, including modulating theoperational parameters in response to preset values or in response tofeedback signals FS from sensor system(s) 175 within the system 100 andprobe working end 110. In one embodiment, as depicted in the blockdiagram of FIG. 3, the system 100 and controller 150 are capable ofproviding or modulating an operational parameter comprising a flow rateof liquid phase treatment media 122 from pressurized source 120, whereinthe flow rate is within a range from about 0.001 to 20 ml/min, 0.010 to10 ml/min or 0.050 to 5 ml/min. The system 100 and controller 150 arefurther capable of providing or modulating another operational parametercomprising the inflow pressure of liquid phase treatment media 121 in arange from 0.5 to 1000 psi, 5 to 500 psi, or 25 to 200 psi. The system100 and controller 150 are further capable of providing or modulatinganother operational parameter comprising a selected level of energycapable of converting the liquid phase media into a non-liquid,non-ionized gas phase media, wherein the energy level is within a rangeof about 5 to 2,500 watts; 10 to 1,000 watts or 25 to 500 watts. Thesystem 100 and controller 150 are capable of applying the selected levelof energy to provide the phase conversion in the treatment media over aninterval ranging from 0.1 second to 10 minutes; 0.5 seconds to 5minutes, and 1 second to 60 seconds. The system 100 and controller 150are further capable of controlling parameters of the vapor phase mediaincluding the flow rate of non-ionized vapor media proximate an outlet125, the pressure of vapor media 122 at the outlet, the temperature ormass average temperature of the vapor media, and the quality of vapormedia as will be described further below.

FIGS. 4A and 4B illustrate a working end 110 of the system 100 of FIG. 2and a method of use. As can be seen in FIG. 4A, a working end 110 issingular and configured as a needle-like device for penetrating intoand/or through a targeted tissue T such as a tumor in a tissue volume176. The tumor can be benign, malignant, hyperplastic or hypertrophictissue, for example, in a patient's breast, uterus, lung, liver, kidney,gall bladder, stomach, pancreas, colon, GI tract, bladder, prostate,bone, vertebra, eye, brain or other tissue. In one embodiment of theinvention, the extension portion 104 is made of a metal, for example,stainless steel. Alternatively or additionally, at least some portionsof the extension portion can be fabricated of a polymer material such asPEEK, PTFE, Nylon or polypropylene. Also optionally, one or morecomponents of the extension portion are formed of coated metal, forexample, a coating with Teflon® to reduce friction upon insertion and toprevent tissue sticking following use. In one embodiment at in FIG. 4A,the working end 110 includes a plurality of outlets 125 that allow vapormedia to be ejected in all radial directions over a selected treatmentlength of the working end. In another embodiment, the plurality ofoutlets can be symmetric or asymmetric axially or angularly about theworking end 110.

In one embodiment, the outer diameter of extension portion 105 orworking end 110 is, for example, 0.2 mm, 0.5 mm, 1 mm, 2 mm, 5 mm or anintermediate, smaller or larger diameter. Optionally, the outlets cancomprise microporosities 177 in a porous material as illustrated in FIG.5 for diffusion and distribution of vapor media flows about the surfaceof the working end. In one such embodiment, such porosities provide agreater restriction to vapor media outflows than adjacent targetedtissue, which can vary greatly in vapor permeability. In this case, suchmicroporosities insure that vapor media outflows will occursubstantially uniformly over the surface of the working end. Optionally,the wall thickness of the working end 110 is from 0.05 to 0.5 mm.Optionally, the wall thickness decreases or increases towards the distalsharp tip 130 (FIG. 5). In one embodiment, the dimensions andorientations of outlets 125 are selected to diffuse and/or direct vapormedia propagation into targeted tissue T and more particularly to directvapor media into all targeted tissue to cause extracellular vaporpropagation and thus convective heating of the target tissue asindicated in FIG. 4B. As shown in FIGS. 4A-4B, the shape of the outlets125 can vary, for example, round, ellipsoid, rectangular, radiallyand/or axially symmetric or asymmetric. As shown in FIG. 5, a sleeve 178can be advanced or retracted relative to the outlets 125 to provide aselected exposure of such outlets to provide vapor injection over aselected length of the working end 110. Optionally, the outlets can beoriented in various ways, for example so that vapor media 122 is ejectedperpendicular to a surface of working end 110, or ejected is at an anglerelative to the axis 115 or angled relative to a plane perpendicular tothe axis. Optionally, the outlets can be disposed on a selected side orwithin a selected axial portion of working end, wherein rotation oraxial movement of the working end will direct vapor propagation andenergy delivery in a selected direction. In another embodiment, theworking end 110 can be disposed in a secondary outer sleeve that hasapertures in a particular side thereof for angular/axial movement intargeted tissue for directing vapor flows into the tissue.

FIG. 4B illustrates the working end 110 of system 100 ejecting vapormedia from the working end under selected operating parameters, forexample a selected pressure, vapor temperature, vapor quantity, vaporquality and duration of flow. The duration of flow can be a selectedpre-set or the hyperechoic aspect of the vapor flow can be imaged bymeans of ultrasound to allow the termination of vapor flows byobservation of the vapor plume relative to targeted tissue T. Asdepicted schematically in FIG. 4B, the vapor can propagateextracellularly in soft tissue to provide intense convective heating asthe vapor collapses into water droplets, which results in effectivetissue ablation and cell death. As further depicted in FIG. 4B, thetissue is treated to provide an effective treatment margin 179 around atargeted tumorous volume. The vapor delivery step is continuous or canbe repeated at a high repetition rate to cause a pulsed form ofconvective heating and thermal energy delivery to the targeted tissue.The repetition rate vapor flows can vary, for example with flow durationintervals from 0.01 to 20 seconds and intermediate off intervals from0.01 to 5 seconds or intermediate, larger or smaller intervals.

In an exemplary embodiment as shown in FIGS. 4A-4B, the extensionportion 105 can be a unitary member such as a needle. In anotherembodiment, the extension portion 105 or working end 110 can be adetachable flexible body or rigid body, for example of any type selectedby a user with outlet sizes and orientations for a particular procedurewith the working end attached by threads or Luer fitting to a moreproximal portion of probe 102.

In other embodiments, the working end 110 can comprise needles withterminal outlets or side outlets as shown in FIGS. 6A-6B. The needle ofFIGS. 6A and 6B can comprise a retractable needle as shown in FIG. 6Ccapable of retraction into probe or sheath 180 for navigation of theprobe through a body passageway or for blocking a portion of the vaporoutlets 125 to control the geometry of the vapor-tissue interface. Inanother embodiment shown in FIG. 6D, the working end 110 can havemultiple retractable needles that are of a shape memory material. Inanother embodiment as depicted in FIG. 6E, the working end 110 can haveat least one deflectable and retractable needle that deflects relativeto an axis of the probe 180 when advanced from the probe. In anotherembodiment, the working end 110 as shown in FIGS. 6F-6G can comprise adual sleeve assembly wherein vapor-carrying inner sleeve 181 rotateswithin outer sleeve 182 and wherein outlets in the inner sleeve 181 onlyregister with outlets 125 in outer sleeve 182 at selected angles ofrelative rotation to allow vapor to exit the outlets. This assembly thusprovides for a method of pulsed vapor application from outlets in theworking end. The rotation can be from about 1 rpm to 1000 rpm.

In another embodiment of FIG. 6H, the working end 110 has a heatapplicator surface with at least one vapor outlet 125 and at least oneexpandable member 183 such as a balloon for positioning the heatapplicator surface against targeted tissue. In another embodiment ofFIG. 6I, the working end can be a flexible material that is deflectableby a pull-wire as is known in the art. The embodiments of FIGS. 6H and6I have configurations for use in treating atrial fibrillation, forexample in pulmonary vein ablation.

In another embodiment of FIG. 6J, the working end 110 includesadditional optional heat applicator means which can comprise amono-polar electrode cooperating with a ground pad or bi-polarelectrodes 184 a and 184 b for applying energy to tissue. In FIG. 6K,the working end 110 includes resistive heating element 187 for applyingenergy to tissue. FIG. 6L depicts a snare for capturing tissue to betreated with vapor and FIG. 6M illustrates a clamp or jaw structure. Theworking end 110 of FIG. 6M includes means actuatable from the handle foroperating the jaws.

Sensors for Vapor Flows, Temperature, Pressure, Quality

Referring to FIG. 7, one embodiment of sensor system 175 is shown thatis carried by working end 110 of the probe 102 depicted in FIG. 2 fordetermining a first vapor media flow parameter, which can consist ofdetermining whether the vapor flow is in an “on” or “off” operatingmode. The working end 110 of FIG. 7 comprises a sharp-tipped needlesuited for needle ablation of any neoplasia or tumor tissue, such as abenign or malignant tumor as described previously, but can also be anyother form of vapor delivery tool. The needle can be any suitable gaugeand in one embodiment has a plurality of vapor outlets 125. In a typicaltreatment of targeted tissue, it is important to provide a sensor andfeedback signal indicating whether there is a flow, or leakage, of vapormedia 122 following treatment or in advance of treatment when the systemis in “off” mode. Similarly, it is important to provide a feedbacksignal indicating a flow of vapor media 122 when the system is in “on”mode. In the embodiment of FIG. 7, the sensor comprises at least onethermocouple or other temperature sensor indicated at 185 a, 185 b and185 c that are coupled to leads (indicated schematically at 186 a, 186 band 186 c) for sending feedback signals to controller 150. Thetemperature sensor can be a singular component or can be plurality ofcomponents spaced apart over any selected portion of the probe andworking end. In one embodiment, a feedback signal of any selectedtemperature from any thermocouple in the range of the heat ofvaporization of treatment media 122 would indicate that flow of vapormedia, or the lack of such a signal would indicate the lack of a flow ofvapor media. The sensors can be spaced apart by at least 0.05 mm, 1 mm,5 mm, 10 mm and 50 mm. In other embodiments, multiple temperaturesensing event can be averaged over time, averaged between spaced apartsensors, the rate of change of temperatures can be measured and thelike. In one embodiment, the leads 186 a, 186 b and 186 c are carried inan insulative layer of wall 188 of the extension member 105. Theinsulative layer of wall 188 can include any suitable polymer or ceramicfor providing thermal insulation. In one embodiment, the exterior of theworking end also is also provided with a lubricious material such asTeflon® which further insures against any tissue sticking to the workingend 110.

Still referring to FIG. 7, a sensor system 175 can provide a differenttype of feedback signal FS to indicate a flow rate or vapor media basedon a plurality of temperature sensors spaced apart within flow channel124. In one embodiment, the controller 150 includes algorithms capableof receiving feedback signals FS from at least first and secondthermocouples (e.g., 185 a and 185 c) at very high data acquisitionspeeds and compare the difference in temperatures at the spaced apartlocations. The measured temperature difference, when further combinedwith the time interval following the initiation of vapor media flows,can be compared against a library to thereby indicate the flow rate.

Another embodiment of sensor system 175 in a similar working end 110 isdepicted in FIG. 8, wherein the sensor is configured for indicatingvapor quality—in this case based on a plurality of spaced apartelectrodes 190 a and 190 b coupled to controller 150 and an electricalsource (not shown). In this embodiment, a current flow is providedwithin a circuit to the spaced apart electrodes 190 a and 190 b andduring vapor flows within channel 124 the impedance will vary dependingon the vapor quality or saturation, which can be processed by algorithmsin controller 150 and can be compared to a library of impedance levels,flow rates and the like to thereby determine vapor quality. It isimportant to have a sensor to provide feedback of vapor quality, whichdetermines how much energy is being carried by a vapor flow. The term“vapor quality” is herein used to describe the percentage of the flowthat is actually water vapor as opposed to water droplets that is notphase-changed. In another embodiment (not shown) an optical sensor canbe used to determine vapor quality wherein a light emitter and receivercan determine vapor quality based on transmissibility or reflectance oflight relative to a vapor flow.

FIG. 8 further depicts a pressure sensor 192 in the working end 110 forproviding a signal as to vapor pressure. In operation, the controllercan receive the feedback signals FS relating to temperature, pressureand vapor quality to thereby modulate all other operating parametersdescribed above to optimize flow parameters for a particular treatmentof a target tissue, as depicted in FIG. 1. In one embodiment, a MEMSpressure transducer is used, which are known in the art. In anotherembodiment, a MEMS accelerometer coupled to a slightly translatablecoating can be utilized to generate a signal of changes in flow rate, ora MEMS microphone can be used to compare against a library of acousticvibrations to generate a signal of flow rates.

Inductive Vapor Generation Systems

FIGS. 9 and 10 depict a vapor generation component that utilizes and aninductive heating system within a handle portion 400 of the probe orvapor delivery tool 405. In FIG. 9, it can be seen that a pressurizedsource of liquid media 120 (e.g., water or saline) is coupled by conduit406 to a quick-connect fitting 408 to deliver liquid into a flow channel410 extending through an inductive heater 420 in probe handle 400 to atleast one outlet 425 in the working end 426. In one embodiment shown inFIG. 9, the flow channel 410 has a bypass or recirculation channelportion 430 in the handle or working end 426 that can direct vapor flowsto a collection reservoir 432. In operation, a valve 435 in the flowchannel 410 thus can direct vapor generated by inductive heater 420 toeither flow channel portion 410′ or the recirculation channel portion430. In the embodiment of FIG. 10, the recirculation channel portion 430also is a part of the quick-connect fitting 408.

In FIG. 9, it can be seen that the system includes a computer controller150 that controls (i) the electromagnetic energy source 440 coupled toinductive heater 420, (ii) the valve 435 which can be anelectrically-operated solenoid, (iii) an optional valve 445 in therecirculation channel 430 that can operate in unison with valve 435, and(iv) optional negative pressure source 448 operatively coupled to therecirculation channel 430.

In general, the system of the invention provides a small handheld deviceincluding an assembly that utilized electromagnetic induction to turn asterile water flow into superheated or dry vapor which is propagatedfrom at least one outlet in a vapor delivery tool to interface withtissue and thus ablate tissue. In one aspect of the invention, anelectrically-conducting microchannel structure or other flow-permeablestructure is provided and an inductive coil causes electric currentflows in the structure. Eddies within the current create magneticfields, and the magnetic fields oppose the change of the main field thusraising electrical resistance and resulting in instant heating of themicrochannel or other flow-permeable structure. In another aspect of theinvention, it has been found that corrosion-resistant microtubes of lowmagnetic 316 SS are best suited for the application, or a sinteredmicrochannel structure of similar material. While magnetic materials canimprove the induction heating of a metal because of ferromagnetichysteresis, such magnetic materials (e.g. carbon steel) are susceptibleto corrosion and are not optimal for generating vapor used to ablatetissue. In certain embodiments, the electromagnetic energy source 440 isadapted for inductive heating of a microchannel structure with afrequency in the range of 50 kHz to 2 Mhz, and more preferably in therange of 400 kHz to 500 kHz. While a microchannel structure is describedin more detail below, it should be appreciated that the scope of theinvention includes flow-permeable conductive structures selected fromthe group of woven filaments structures, braided filament structures,knit filaments structures metal wool structures, porous structures,honeycomb structures and an open cell structures.

In general, a method of the invention comprises utilizing an inductiveheater 420 of FIGS. 9-10 to instantly vaporize a treatment media such asde-ionized water that is injected into the heater at a flow rate ofranging from 0.001 to 20 ml/min, 0.010 to 10 ml/min, 0.050 to 5 ml/min.,and to eject the resulting vapor into body structure to ablate tissue.The method further comprises providing an inductive heater 420configured for a disposable had-held device (see FIG. 9) that is capableof generating a minimum water vapor that is at least 70% water vapor,80% water vapor and 90% water vapor.

FIG. 10 is an enlarged schematic view of inductive heater 420 whichincludes at least one winding of inductive coil 450 wound about aninsulative sleeve 452. The coil 450 is typically wound about a rigidinsulative member, but also can comprise a plurality of rigid coilportions about a flexible insulator or a flexible coil about a flexibleinsulative sleeve. The coil can be in handle portion of a probe or in aworking end of a probe such as a catheter. The inductive coil canextends in length at least 5 mm, 10 mm, 25 mm, 50 mm or 100 m.

In one embodiment shown schematically in FIG. 10, the inductive heater420 has a flow channel 410 in the center of insulative sleeve 452wherein the flows passes through an inductively heatable microchannelstructure indicated at 455. The microchannel structure 455 comprises anassembly of metal hypotubes 458, for example consisting of thin-wallbiocompatible stainless steel tube tightly packed in bore 460 of theassembly. The coil 450 can thereby inductively heat the metal walls ofthe microchannel structure 455 and the very large surface area ofstructure 455 in contact with the flow can instantly vaporize theflowable media pushed into the flow channel 410. In one embodiment, aceramic insulative sleeve 452 has a length of 1.5″ and outer diameter of0.25″ with a 0.104″ diameter bore 460 therein. A total of thirty-two 316stainless steel tubes 458 with 0.016″ O.D., 0.010″ I.D., and 0.003″ wallare disposed in bore 460. The coil 450 has a length of 1.0″ andcomprises a single winding of 0.026″ diameter tin-coated copper strandwire (optionally with ceramic or Teflon® insulation) and can be wound ina machined helical groove in the insulative sleeve 452. A 200 W RF powersource 440 is used operating at 400 kHz with a pure sine wave. Apressurized sterile water source 120 comprises a computer controlledsyringe that provides fluid flows of deionized water at a rate of 3ml/min which can be instantly vaporized by the inductive heater 420. Atthe vapor exit outlet or outlets 125 in a working end, it has been foundthat various pressures are needed for various tissues and body cavitiesfor optimal ablations, ranging from about 0.1 to 20 psi for ablatingbody cavities or lumens and about 1 psi to 100 psi for interstitialablations.

Now turning to FIGS. 11A-11C, a working end that operates similarly tothat of FIG. 2 is shown. This embodiment comprises an extension memberor other device 540 that can be positioned within a body region as shownin FIG. 11A. The device 540 includes a working end 570 that carries anevertable expansion structure or balloon 575 in interior bore 576. Theexpansion structure or balloon 575 is everted from within the deviceinto the body region to apply energy to target tissue in the region asdescribed below. By employing via everting, the structure 575 can fillor conform to a desired area within target region. In variations of thedevice, an everting balloon 575 can be fully positioned within thedevice 540 prior to everting. Alternatively, the everting balloon 575can partially extend from an opening in the device 540 and then everted.FIGS. 11B-11C illustrate the balloon 575 being everted by application offluid generated pressure from a first fluid source 577 (which can be anylow pressure gas in a syringe) within a body cavity 578, for example, acavity in gall bladder 580. However, additional variations of deviceswithin this disclosure can employ any number of means to evert theballoon 575 from the device 540.

The region containing the target tissue includes any space, cavity,passage, opening, lumen or potential space in a body such as a sinus,airway, blood vessel, uterus, joint capsule, GI tract lumen orrespiratory tract lumen. As can be seen in FIG. 11C, the expandablestructure 575 can include a plurality of different dimension vaporoutlets 585, for locally controlling the ejection pressure of a volumeof ejected condensable vapor, which in turn can control the depth andextent of the vapor-tissue interaction and the corresponding depth ofablation. In embodiments described further below, the energy-emittingwall or surface 588 of the expandable structure can carry RF electrodesfor applying additional energy to tissue. Light energy emitters ormicrowave emitters also can be carried by the expandable structure. Avapor flow from source 590 or from any vapor generator source describedabove can flow high quality vapor from the vapor ports 585 in the wallor surface 588. The vapor outlets can be dimensioned from about 0.001″in diameter to about 0.05″ and also can be allowed to be altered indiameter under selected pressures and flow rates. The modulus of apolymer wall 588 also can be selected to control vapor flows through thewall

In general, a method of the invention as in FIG. 11C for treating a bodycavity or luminal tissue comprises (a) everting and/or unfurling athin-wall structure into the body cavity or lumen, and (b) applying atleast 25 W, 50 W, 75 W, 100 W, 125 W and 150 W from an energy-emittersurface of the structure to the tissue, for example, the endometrium forablation thereof in a global endometrial ablation procedure. In oneembodiment, the method applies energy that is provided by a condensablevapor undergoing a phase change. In one embodiment, the method deliversa condensable vapor that provides energy of at least 250 cal/gm, 300cal/gm, 350 cal/gm, 400 cal/gm and 450 cal/gm. Also, the method canapply energy provided by at least one of a phase change energy release,light energy, RF energy and microwave energy.

FIGS. 12A-12C depict another embodiment of vapor delivery system 600that is configured for treating esophageal disorders, such as Barrett'sesophagus, dysplasia, esophageal varices, tumors and the like. Theobjective of a treatment of an esophageal disorder is to ablate a thinlayer of the lining of the esophagus, for example, from about 0.1 mm to1.0 mm in depth. Barrett's esophagus is a severe complication of chronicgastroesophageal reflux disease (GERD) and seems to be a precursor toadenocarcinoma of the esophagus. The incidence of adenocarcinoma of theesophagus due to Barrett's esophagus and GERD is on the rise. In onemethod of the invention, vapor delivery can be used to ablate a thinsurface layer including abnormal cells to prevent the progression ofBarrett's esophagus.

The elongated catheter or extension member 610 has a first end or handleend 612 that is coupled to extension member 610 that extends to workingend 615. The extension member 610 has a diameter and length suitable foreither a nasal or oral introduction into the esophagus 616. The workingend 615 of the extension member is configured with a plurality ofexpandable structures such as temperature resistant occlusion balloons620A, 620B. 620C and 620D. In one embodiment, the balloons can becomplaint silicone. In other embodiment, the balloons can benon-compliant thin film structures. The handle end 612 includes amanifold 622 that couples to multiple lumens to a connector 625 thatallows for each balloon 620A, 620B, 620C and 620D to be expandedindependently, for example, with a gas or liquid inflation sourceindicated at 630. The inflation source 630 can be a plurality ofsyringes, or a controller can be provided to automatically pump a fluidto selected balloons. The number of balloons carried by extension member610 can range from 2 to 10 or more. As can be understood in FIGS.12A-12C, the extension member 610 has independent lumens thatcommunicate with interior chambers of balloons 620A, 620B, 620C and620D.

Still referring to FIG. 12A, the handle and extension member 610 have apassageway 632 therein that extends to an opening 635 or window to allowa flexible endoscope 638 to view the lining of the esophagus. In onemethod, a viewing means 640 comprises a CCD at the end of endoscope 638that can be used to view an esophageal disorder such as Barrett'sesophagus in the lower esophagus as depicted in FIG. 12A. The assemblyof the endoscope 638 and extension member 610 can be rotated andtranslated axially, as well as by articulation of the endoscope's distalend. Following the step of viewing the esophagus, the distal balloon620D can be expanded as shown in FIG. 12B. In one example, the distalballoon 620D is expanded just distal to esophageal tissue targeted forablative treatment with a condensable vapor. Next, the proximal balloon620A can be expanded as also shown in FIG. 12B. Thereafter, the targetedtreatment area of the esophageal lining can be viewed and additionalocclusion balloons 620B and 620C can be expanded to reduce the targetedtreatment area. It should be appreciated that the use of occlusionballoons 620A-620D are configured to control the axial length of a vaporablation treatment, with the thin layer ablation occurring in 360°around the esophageal lumen. In another embodiment, the plurality ofexpandable members can include balloons that expand to engage only aradial portion of the esophageal lumen for example 90°, 180° or 270° ofthe lumen. By this means of utilizing occlusion balloons of a particularshape or shapes, a targeted treatment zone of any axial and radialdimension can be created. One advantage of energy delivery from a phasechange is that the ablation will be uniform over the tissue surface thatis not contacted by the balloon structures.

FIG. 12C illustrates the vapor delivery step of the method, wherein ahigh temperature water vapor is introduced through the extension member610 and into the esophageal lumen to release energy as the vaporcondenses. In FIG. 12C, the vapor is introduced through an elongatedcatheter 610 that is configured with a distal end 655 that is extendableslightly outside port 635 in the extension member 610. A vapor source660, such as the vapor generator of FIG. 9 is coupled to the handle end612 of the catheter. The catheter distal end 655 can have arecirculating vapor flow system as disclosed in commonly invented andco-pending application Ser. No. 12/167,155 filed Jul. 2, 2008. Inanother embodiment, a vapor source 660 can be coupled directly to a portand lumen 664 at the handle end 612 of extension member 610 to delivervapor directly through passageway 632 and outwardly from port 635 totreat tissue. In another embodiment, a dedicated lumen in extensionmember 610 can be provided to allow contemporaneous vapor delivery anduse of the viewing means 640 described previously.

The method can include the delivery of vapor for less than 30 seconds,less than 20 seconds, less than 10 seconds or less than 5 seconds toaccomplish the ablation. The vapor quality as described above can begreater than 70%, 80% or 90% and can uniformly ablate the surface of theesophageal lining to a depth of up to 1.0 mm.

In another optional aspect of the invention also shown in FIGS. 12A-12C,the extension member 610 can include a lumen, for example the lumenindicated at 664, that can serve as a pressure relief passageway.Alternatively, a slight aspiration force can be applied to the lumenpressure relief lumen from negative pressure source 665.

FIG. 13 illustrates another aspect of the invention wherein a singleballoon 670 can be configured with a scalloped portion 672 for ablatingtissue along one side of the esophageal lumen without a 360 degreeablation of the esophageal lumen. In this illustration the expandablemember or balloon 670 is radially positioned relative to at least onevapor outlet 675 to radially limit the condensable vapor from engagingthe non-targeted region. As shown, the balloon 670 is radially adjacentto the vapor outlet 675 so that the non-targeted region of tissue iscircumferentially adjacent to the targeted region of tissue. Although,the scalloped portion 672 allows radial spacing, alternative designsinclude one or more shaped balloons or balloons that deploy to a side ofthe port 675. FIG. 13 also depicts an endoscope 638 extended outwardfrom port 635 to view the targeted treatment region as the balloon 670is expanded. The balloon 670 can include internal constraining webs tomaintain the desired shape. The vapor again can be delivered through avapor delivery tool or through a dedicated lumen and vapor outlet 675 asdescribed previously. In a commercialization method, a library ofcatheters can be provided that have balloons configured for a series ofless-than-360° ablations of different lengths.

FIGS. 14-15 illustrate another embodiment and method of the inventionthat can be used for tumor ablation, varices, or Barrett's esophagus inwhich occlusion balloons are not used. An elongate vapor deliverycatheter 700 is introduced along with viewing means to locally ablatetissue. In FIG. 14, catheter 700 having working end 705 is introducedthrough the working channel of gastroscope 710. Vapor is expelled fromthe working end 705 to ablate tissue under direct visualization. FIG. 15depicts a cut-away view of one embodiment of working end in which vaporfrom source 660 is expelled from vapor outlets 720 in communication withinterior annular vapor delivery lumen 722 to contact and ablate tissue.Contemporaneously, the negative pressure source 655 is coupled tocentral aspiration lumen 725 and is utilized to suction vapor flows backinto the working end 705. The modulation of vapor inflow pressure andnegative pressure in lumen 725 thus allows precise control of thevapor-tissue contact and ablation. In the embodiment of FIG. 15, theworking end can be fabricated of a transparent heat-resistant plastic orglass to allow better visualization of the ablation. In the embodimentof FIG. 15, the distal tip 730 is angled, but it should be appreciatedthat the tip can be square cut or have any angle relative to the axis ofthe catheter. The method and apparatus for treating esophageal tissuedepicted in FIGS. 14-15 can be use to treat small regions of tissue, orcan be used in follow-up procedures after an ablation accomplished usingthe methods and systems of FIGS. 12A-13.

In any of the above methods, a cooling media can be applied to thetreated esophageal surface, which can limit the diffusion of heat in thetissue. Besides a cryogenic spray, any cooling liquid such as cold wateror saline can be used.

FIGS. 16A-16F depict another embodiment of vapor delivery system 800that is configured for treating a body cavity with an everting thin-wallstructure similar to that of FIGS. 11A-11C, and more particularly isconfigured for treating a uterine cavity in an endometrial ablationprocedure. The system 800 also has features that are similar to theembodiment of FIGS. 12A-12C in that a plurality of balloons are carriedabout the shaft of introducer 810 to occlude or contact tissue toprevent vapor contact with tissue. FIG. 16A depicts a patient's uterus812 with uterine cavity 814, endometrial lining 816, and myometrium 818.The cervix 820 is the lower, narrow portion of the uterus 812 that joinswith the top end of the vagina 822. The passageway between the externalos 824 and the uterine cavity 814 is referred to as the endocervicalcanal 825, which varies in length and width, along with the cervix 820overall. The endocervical canal 825 terminates at the internal os 828that is the opening of the cervix within the uterine cavity 814.

Endometrial ablation is a procedure that ablates the endometrial liningof a uterus. This technique is most often employed for women who sufferfrom excessive or prolonged bleeding during their menstrual cycle. It isimportant to prevent any ablation of the endocervical canal 825 duringsuch a global endometrial ablation procedure. The length of endocervicalcanals 825 can vary greatly among patients, for example from less than10 mm to more than 30 mm, thus making it necessary to provide anablation system that can be suited for various patient anatomies.Further, some aspects of the ablation must be accomplished withoutdirect visualization, thus requiring systems and methods that confinethe ablation to the endometrial lining while at the same time protectingthe endocervical canal.

In FIG. 16A, it can be seen the working end 835 of shaft 810 carries aplurality of expansion members or balloons 840A-840D which can range innumber from 2 to 10 or more. The expansion members can be expanded andcollapsed sequentially, and based on sensory feedback (tactile feedbackor pressure feedback), the operator or a controller can determine thetransition between the endocervical canal 825 and the uterine cavity 814and thus determine the optimal location for leaving a deployed balloonfor sealing and protecting the endocervical canal. The working end 835of FIG. 16A provides four axially extending balloons 840A, 840B, 840Cand 840D. The first or proximal-most balloon can be elongated and haveany suitable length, for example, ranging from 10 mm to 50 mm foroccupying the substantial portion of a patient's endocervical canal. Theadjacent balloons 840B-840D can have a shorter axial dimension, forexample from about 2 mm to 5 mm length. The diameter of shaft 810 canrange from about 3 mm to 7 mm to accommodate an evertable balloon member850 (FIG. 16F) in an interior space 852 in introducer 810 (FIG. 16A).

FIG. 16A depicts an initial step in a method of the invention whereinthe physician introduces the distal end 835 of the device through theendocervical canal 825 to an estimated location or depth within theuterine cavity 814. The proximal balloon is configured with dimensionalmarkers 854 that indicate to the surgeon the depth of insertion of theworking end 835 relative to the external os 824. The physician candetermine the size of the uterine cavity and the length of theendocervical canal 825 in a sounding procedure prior to introducing theworking end 835 into the patient, and by this means can estimate thedesired insertion distance as depicted in FIG. 16A. The physicianselects an insertion distance that positions the distal end 855 ofballoon 840A at the internal os 828 of the uterus, or somewhat proximalfrom the internal os. After the physician introduces the working end asin FIG. 16A, the physician actuates an inflation source 860 to inject aflow media though a lumen in introducer 810 to expand the proximalballoon 840A as shown in FIG. 16B. Alternatively, a controller 865 canbe used to inject flow media to expanded balloon 840A. In one method,the expansion of the balloon can be terminated at a pre-selectedpressure of between about 0.50 psi and 10 psi.

FIGS. 16C-16E depict subsequent steps corresponding to a method of theinvention wherein the inflation source 860 is actuated to sequentiallyto expand balloons 840B-840D to further occlude or seal the endocervicalcanal 825. FIG. 16C depicts balloon 840B after being expanded. FIG. 16Ddepicts balloon 840C after being expanded and FIG. 16E depicts balloon840D after being expanded. The physician can use tactile feedback or thecontroller 865 can sense a relevant expansion parameter such as balloonpressure or volume to characterize the tissue being engaged by eachballoon. By this means, it can be determined which balloon is proximatethe internal os 828 since the expansion of a balloon within theendocervical canal 825 will be more constrained than the expansion of aballoon inward of the internal os 828 that expands outward against theendometrium 816. Thus, the physician or controller 865 can select whichballoons to expand to protect the endocervical canal 825 and whichballoons can be collapsed to allow treatment of endometrium 816. In FIG.16F, it can be seen that the distalmost balloon 840D is collapsed andthe more proximal balloons 840B and 840C are expanded to protect tissueand seal the endocervical canal 825.

FIG. 16F also depicts the subsequent step of introducing an expandablemember 850 into the uterine cavity from interior space 852 in introducer810. In one embodiment, the expandable member is an evertable balloonsimilar to that shown in FIGS. 11A-11C. The expandable structure 850alternatively can be a fluid expandable member that is axially advancedinto the uterine cavity and then expanded. In either case, a vaporsource 880A and controller 880B as described above communicates with alumen in introducer 810 and a plurality of vapor outlets 885 in thesurface of structure 850 to apply energy to ablate the endometrium 816to a selected depth, for example, and ablation depth of 3 mm to 6 mm. Ithas been found that delivering a water vapor having a quality of 80% or90% can provide a uniform ablation to a selected depth of 4 mm to 6 mmwith a vapor delivery time ranging between 60 seconds and 120 seconds.The method comprises delivering energy of at least 25 W, 50 W, 75 W, 100W, 125 W and 150 W into the uterine cavity to ablate the endometrium.

In the embodiment of FIG. 16F, it can be seen that vapor media can beexpelled from vapor outlets 885 which are distributed about the surfaceof structure 850 that is desirable to insure vapor delivery to allsurfaces of the uterine cavity. Often, the patient will have one or morefibroids that can vary widely in size and which can impinge on theuterine cavity 814 and thus prevent vapor flow and contact with allportions of the endometrium. Thus, a method of the invention comprisesproviding a vapor flow into a body cavity from a plurality of vaporoutlets 885 distributed about all surfaces of an expandable structure850 that is expanded in the body cavity. As can be understood from FIG.16F, an objective of the invention is to have the expandable structureexpand to occupy a substantial portion of the cavity to therebydistribute the vapor ports 885 within a substantial portion of thecavity 814 that may be impinged on by fibroids. However, it is notnecessary to provide an expandable structure that contacts all surfacesof the cavity. The expelled vapor will naturally propagate to allnon-impinged regions of the uterine cavity 814 to thereby create atreated or ablated region 886 of the endometrium (cross-hatched region)as shown in FIG. 16F. As can also be seen in FIG. 16F, a pressurerelieving lumen 888 is provided in introducer 810 to allow a selectedpressure to develop within the uterine cavity 814, for example rangingfrom 10 mm Hg to 100 mm Hg, or between 25 mm Hg and 500 mm Hg. Thesystem also can include an optional negative pressure source 890 that iscoupled to the pressure relieving lumen 888 to evacuate vapor from thebody cavity, and a controller 880B can coupled to the negative pressuresource 890 (or pressure relief valve) to control pressure in the uterinecavity.

FIG. 17 illustrates lateral schematic sectional view of the working end835 deployed in the patient as in FIG. 16F. It can be seen that a normalpatient anatomy includes the uterus 812 and uterine cavity lying in acurved plane that is not aligned with the vagina 822. For this reason,it can be understood that an everting structure 850 as depicted in FIGS.11A-11C and 16A-16F can provide an atraumatic method of deploying anablation device within the uterine cavity. It can be easily understoodthat an everting or unrolling thin-film structure 850 can deployatraumatically within a curved space or curved potential space, whichprovides a distinct advantage over other commercially availableendometrial ablation tools that use a substantially rigid, straightintroducer to introduce an ablation instrument into the uterine cavity.Thus, a method of the invention comprises ablating tissue by (a)deploying a thin-wall evening structure into a body cavity, lumen orpassageway, and (b) applying at least 25 W, 50 W, 75 W, 100 W, 125 W and150 W from a surface portion of the everting structure to thereby ablatea wall of the body cavity. As will be described below, the energydelivery surface can include RF electrodes coupled to an RF source incombination with an energy release from a condensable vapor.

FIG. 18 depicts another embodiment of expandable structure 900 that isevertable from introducer 910 and is similar to that of FIG. 16F exceptthat it further includes multiple opposing polarity electrode surfaceportions 915A and 915B indicated with (+) and (−) polarities. In FIG.18, the occlusion balloons 840A-840D of FIGS. 16A-16F are not shown forconvenience. In the embodiment of FIG. 18, the vapor can be deliveredthrough vapor outlets 885 from vapor source 880A and controller 880B asdescribed previously. Contemporaneously, the RF source 925 can beactuated to provide bi-polar energy delivery to engage tissue by meansof the electrode surface portions 915A and 915B. The expandablestructure 900 can be a thin film compliant or non-compliant materialwith the electrodes consisting of a thin layer coating or laminate. Thevapor further can comprise a saline vapor that will provide additionalelectrically conductive media in the uterine cavity that can enhance RFenergy application to the targeted tissue. FIG. 18 further depicts atleast one flexible extendable member 930 that can be extended fromintroducer 910. The extendable member 930 includes multiple ports 935that communicate with a pressure relief lumen 940 to relieve or maintaina selected pressure in the uterine cavity. The extendable member 930 canbe extended after deployment of the expandable structure that hasunfurled and opened the cavity. The extendable member 930 thus providesa plurality of ports 935 within the uterine cavity to function aspressure relieving ports, and thus if any particular port is occluded bytissue impinging on it or by tissue detritus blocking such a port, therestill will be other spaced apart ports 935 for relieving pressure. Theextendable member 930 and pressure relief lumen 940 therein can beoperatively coupled to negative pressure source 890 and controller 880Bas described above to maintain or modulate pressure in the uterinecavity during energy application. Clearly, the electrodes 915A, 915B andRF source 925 can be replaced with a microwave antenna, a laser fiber,ultrasound transducer, resistive heater, as well as the respective powersupply. Any other energy modality can be employed as well. Such a designcan be applied to any of the devices described herein.

FIG. 19 is a sectional view of the evertable, expandable structure 900of FIG. 18 that shows that channels 944 are provided in the surface ofthe evertable structure 900. Each channel thus can carry vapor to aplurality of outlets 885 as can be understood from FIGS. 16F and 18. Thecentral chamber 948 of the evertable structure can be inflated to eventhe structure, and thereafter the structure can be collapsed. In otherwords, the evertable structure 900 is configured to unfurl a surfacecarrying the vapor delivery channels 944 within the uterine cavity.

Another method of the invention is depicted in FIG. 20 that relates touse of a vapor delivery catheter system 1000 that is similar toembodiments described above for treating a diabetic disorder. Type 2diabetes is a complex disease in which cells in the body arenon-responsive to a crucial insulin signal in a process known as insulinresistance. Insulin is a hormone produced by the pancreas that helpscells of the body absorb glucose, which is their main energy source forcells. In Type 2 diabetes, the cells cannot use the insulin, and glucosebuilds up in the bloodstream. Initially, the pancreas can overcompensateby producing more insulin. However, the pancreas eventually cannotsecrete enough insulin to overcome the resistance, and cells leave thebody with excess glucose that cannot be used. High levels of glucose inthe bloodstream can damage organs, including the kidneys and the heart,and can lead to blindness. It has been found that gastric bypasssurgeries that re-work the upper intestine can have a significant impactin the regulation of glucose, and can also be involved in resolving Type2 diabetes.

There are multiple theories on how changes in gut hormones after gastricbypass surgery can cause diabetes to disappear. One hypothesis isfocused on the portion of the gut that is bypassed in surgery—the uppersmall intestine. This section of the intestine may secrete hormones thatactually cause insulin resistance. A bypass of this portion of the smallintestine thus would prevent the release of such hormones. Without thehormones, insulin resistance would diminish and diabetes symptoms woulddisappear.

A method corresponding to the invention comprises using vapor to applyablative energy to the lumen of a patient's duodenum and/or portions ofintestine as illustrated schematically in FIG. 20. A very thin layerablation can close the terminal portions of secretory ducts and alsoablate receptors that likely play a role in hormone release.

In FIG. 20, a cut-away view of a stomach 1002, duodenum 1004 andintestine 1006 is shown. The targeted site 1010 is accessed in atrans-esophageal approach with the working end 1025 of vapor deliverycatheter 1000. The targeted treatment site 1010 can be a suitable lengththat may be from about 1 cm to 40 cm or more. In one embodiment, thecatheter 1000 has an interior passageway 1030 that is coupled to a vaporsource 660 as described in other embodiments above. The catheter can beintroduced into the stomach by viewing with a gastroscope (not shown).In one embodiment, the catheter 1000 has a proximal occlusion balloon1040A that is configured to occlude the intestinal lumen at the junctionwith the stomach. The balloon 1040A can comprise balloon portions havingvaried diameters for gripping the intestinal and stomach lumens, forexample, as depicted in FIG. 20. The working end 1025 is furtherconfigured with a plurality of expandable balloons, for example balloons1040B-1040F in FIG. 20, which is similar to the catheter of FIGS.12A-12C. A selected balloon or number of balloons can thus be expandedto occlude the intestinal lumen to provide a targeted treatment site1010 between the balloons. A high temperature condensable vapor can bedelivered as described above to cause a very thin layer ablation.

In general, a method of the invention for altering function of adigestive tract wall comprises introducing a heated vapor media into atargeted site in at least a portion of a digestive tract sufficient toalter function. In this method, the vapor media condenses to applyenergy uniformly about the targeted site. The applied energy ablatesstructures, secretory ducts or receptors in the tract wall, denaturescollagen in the tract wall or ablates structures in a thin surface layerof the tract wall. A vapor media can have a temperature of at least 60°C., 70° C., 80° C., 90° C. or 100° C.

In one method, the applied energy alters digestive function to treatdiabetes. In one method, the duodenum is treated to alleviate a diabeticdisorder. The method includes applying energy between first and secondocclusion balloons. Another method of treating diabetes compriseintroducing a catheter working end into a patient's intestine and/orstomach, and applying energy from the working end modify tissue to treatdiabetes. The applied energy can be between 0.01 Watts and 50 Watts, orbetween 0.1 Watts and 10 Watts. The energy can be applied within aninterval of 0.1 second to 120 seconds or 1 second to 30 seconds. Themethod can include a vapor that carries a second composition, such as apharmacologic agent.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration and the above description of theinvention is not exhaustive. Specific features of the invention areshown in some drawings and not in others, and this is for convenienceonly and any feature may be combined with another in accordance with theinvention. A number of variations and alternatives will be apparent toone having ordinary skills in the art. Such alternatives and variationsare intended to be included within the scope of the claims. Particularfeatures that are presented in dependent claims can be combined and fallwithin the scope of the invention. The invention also encompassesembodiments as if dependent claims were alternatively written in amultiple dependent claim format with reference to other independentclaims.

What is claimed is:
 1. A method of treating a diabetic disorder of apatient, the method comprising: inserting a working end of a vapordelivery tool into an intestinal lumen of the patient; delivering avapor to a surface area of an intestinal lumen tissue of the patient totransfer energy to the intestinal lumen tissue in a controlled manner toheat the intestinal lumen tissue while preventing the vapor fromcontacting an adjacent surface of the intestinal lumen tissue such thatthe vapor causes limited ablation of the surface area the intestinallumen tissue; and repeating delivery of the vapor to the surface of theintestinal lumen of tissue such that the target area is sufficient toalter a digestive function of the patient.
 2. The method of claim 1,wherein the vapor has a temperature of at least 60° C.
 3. The method ofclaim 1, wherein the vapor comprises water vapor.
 4. The method of claim1, further comprising vaporizing liquid water to create the vapor. 5.The method of claim 1, further comprising generating a flow of the vaporthrough the working end to the intestinal lumen tissue, wherein thevapor is generated from at least one of water, saline, and alcohol. 6.The method of claim 1, wherein the vapor delivery tool comprises aflexible catheter.
 7. The method of claim 1, further comprisingvaporizing a fluid proximal to the working end of the vapor introductiontool.
 8. The method of claim 1, further comprising introducing at leastone substance with the vapor.
 9. The method of claim 8, wherein the atleast one substance is at least one of a therapeutic agent and apharmacological agent.
 10. The method of claim 1, further comprisingintroducing at least one active agent with the vapor.
 11. The method ofclaim 10, wherein the at least one active agent is at least one of ananesthetic, an antibiotic, a toxin, a sclerosing agent, an alcohol, andan enhancing media.
 12. The method of claim 1, where the working endincludes at least one expansion structure, and further comprisingexpanding the at least one expansion structure in the intestinal lumenagainst the adjacent surface of the intestinal lumen tissue to preventthe vapor from contacting the adjacent surface which preventsmodification of the adjacent surface of the intestinal lumen.
 13. Themethod of claim 1, where the intestinal lumen comprises a duodenum. 14.The method of claim 1, where delivering vapor comprises delivering acondensable vapor.